expanddir.c revision 230272c15a71edfd53bc805adf560d0386dddff3 
1/*
2 * expand.c --- expand an ext2fs directory
3 *
4 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999  Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
9 * %End-Header%
10 */
11
12#include "config.h"
13#include <stdio.h>
14#include <string.h>
15#if HAVE_UNISTD_H
16#include <unistd.h>
17#endif
18
19#include "ext2_fs.h"
20#include "ext2fs.h"
21
22struct expand_dir_struct {
23	int		done;
24	int		newblocks;
25	blk64_t		goal;
26	errcode_t	err;
27};
28
29static int expand_dir_proc(ext2_filsys	fs,
30			   blk64_t	*blocknr,
31			   e2_blkcnt_t	blockcnt,
32			   blk64_t	ref_block EXT2FS_ATTR((unused)),
33			   int		ref_offset EXT2FS_ATTR((unused)),
34			   void		*priv_data)
35{
36	struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
37	blk64_t	new_blk;
38	char		*block;
39	errcode_t	retval;
40
41	if (*blocknr) {
42		if (blockcnt >= 0)
43			es->goal = *blocknr;
44		return 0;
45	}
46	if (blockcnt &&
47	    (EXT2FS_B2C(fs, es->goal) == EXT2FS_B2C(fs, es->goal+1)))
48		new_blk = es->goal+1;
49	else {
50		es->goal &= ~EXT2FS_CLUSTER_MASK(fs);
51		retval = ext2fs_new_block2(fs, es->goal, 0, &new_blk);
52		if (retval) {
53			es->err = retval;
54			return BLOCK_ABORT;
55		}
56		es->newblocks++;
57		ext2fs_block_alloc_stats2(fs, new_blk, +1);
58	}
59	if (blockcnt > 0) {
60		retval = ext2fs_new_dir_block(fs, 0, 0, &block);
61		if (retval) {
62			es->err = retval;
63			return BLOCK_ABORT;
64		}
65		es->done = 1;
66		retval = ext2fs_write_dir_block(fs, new_blk, block);
67	} else {
68		retval = ext2fs_get_mem(fs->blocksize, &block);
69		if (retval) {
70			es->err = retval;
71			return BLOCK_ABORT;
72		}
73		memset(block, 0, fs->blocksize);
74		retval = io_channel_write_blk64(fs->io, new_blk, 1, block);
75	}
76	if (blockcnt >= 0)
77		es->goal = new_blk;
78	if (retval) {
79		es->err = retval;
80		return BLOCK_ABORT;
81	}
82	ext2fs_free_mem(&block);
83	*blocknr = new_blk;
84
85	if (es->done)
86		return (BLOCK_CHANGED | BLOCK_ABORT);
87	else
88		return BLOCK_CHANGED;
89}
90
91errcode_t ext2fs_expand_dir(ext2_filsys fs, ext2_ino_t dir)
92{
93	errcode_t	retval;
94	struct expand_dir_struct es;
95	struct ext2_inode	inode;
96
97	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
98
99	if (!(fs->flags & EXT2_FLAG_RW))
100		return EXT2_ET_RO_FILSYS;
101
102	if (!fs->block_map)
103		return EXT2_ET_NO_BLOCK_BITMAP;
104
105	retval = ext2fs_check_directory(fs, dir);
106	if (retval)
107		return retval;
108
109	es.done = 0;
110	es.err = 0;
111	es.goal = 0;
112	es.newblocks = 0;
113
114	retval = ext2fs_block_iterate3(fs, dir, BLOCK_FLAG_APPEND,
115				       0, expand_dir_proc, &es);
116
117	if (es.err)
118		return es.err;
119	if (!es.done)
120		return EXT2_ET_EXPAND_DIR_ERR;
121
122	/*
123	 * Update the size and block count fields in the inode.
124	 */
125	retval = ext2fs_read_inode(fs, dir, &inode);
126	if (retval)
127		return retval;
128
129	inode.i_size += fs->blocksize;
130	ext2fs_iblk_add_blocks(fs, &inode, es.newblocks);
131
132	retval = ext2fs_write_inode(fs, dir, &inode);
133	if (retval)
134		return retval;
135
136	return 0;
137}
138